L&LB Langmuir and Langmuir-Blodgett
KSV NIMA Langmuir and Langmuir-Blodgett Troughs are the leading and most widely used instruments for Langmuir film fabrication, Langmuir film characterization (including microscopy) as well as Langmuir-Blodgett film deposition.
KSV NIMA Langmuir and Langmuir-Blodgett Deposition Troughs are used for the fabrication and characterisation of single molecule thick films and offer the precision control over the lateral packing density of molecules.
Following characterisation studies of the unique properties of molecules in monolayers, the instruments can also be used to transfer these monolayers using a Langmuir-Blodgett or Langmuir-Schaefer deposition technique. This enables the creation of single and multilayer films with precise control of thickness, molecular orientation and packing density.
The fabrication of insoluble monolayers, at either the gas-liquid or liquid-liquid interface, with controlled packing densities (Langmuir films) and the creation and transfer of such well-ordered functional films to solid surfaces (Langmuir-Blodgett films) find use in a myriad of nanotechnology applications:
- Biomembranes and biomolecular interactions
- Cell membrane model (e.g. protein and ion interactions)
- Conformational changes and reactions
- Drug delivery and behaviour
- Organic and inorganic coatings
- Functional coatings with optical, electrical and structural properties
- Novel coatings of nanotubes, nanowires, graphene etc.
- Surface reactions
- Immunological and enzyme-substrate reactions
- Biosensors and surface immobilized catalysts
- Surface adsorption and desorption
- Surfactants and colloids
- Colloid stability
- Emulsion, dispersion, foam stability
- Rheology of thin films
- Dilational rheology
- Interfacial shear rheology (with the KSV NIMA ISR)
Langmuir Troughs -L
Langmuir Troughs are used to create, modify and study monolayers at either the gas-liquid or liquid-liquid interface (Langmuir films).
A Langmuir film can be defined as an insoluble monolayer of functional molecules, nanoparticles, nanowires or microparticles that reside at the gas-liquid or liquid-liquid interface. The fact that these molecules can move freely at the interface provide great flexibility for controlling the packing density and studying monolayer behaviour.
Once compressed, a monolayer film can be considered to be a two-dimensional solid film with a surface area to volume ratio far above that of bulk materials. At these conditions, materials often yield fascinating new properties. The Langmuir Trough allows you to infer how particular molecules pack together while confined in two dimensions. The surface pressure-area isotherm can also provide a measure of the average area per molecule and the compressibility of the monolayer.
In a typical isotherm measurement a monolayer is organized under compression, starting from a two dimensional gas phase (G) moving through a liquid phase (L) to a fully organized solid phase (S). In the gas phase the molecules are not strongly interacting with each other.
When the surface area is decreased the molecules become more closely packed and start to interact with each other. At the solid phase the molecules are completely organized and the surface pressure increases
dramatically. At the maximum surface pressure the collapse point is reached after which the monolayer packing is no longer controlled.
Langmuir-Blodgett troughs- LB
A Langmuir-Blodgett Deposition Trough is very similar to a Langmuir Trough.
It enables Langmuir film fabrication at the gas-liquid interface and is equipped with a dipping well and a dipping mechanism for Langmuir film deposition onto solid substrates at a desired packing density (typically in the solid phase). Once a Langmuir film has been deposited it is referred to as a Langmuir-Blodgett film.
Following compression, Langmuir-Blodgett Troughs are used to transfer Langmuir films to solid substrates in a controlled manner. In the case of Langmuir-Blodgett (LB) deposition the sample is moved vertically through the monolayer while the Langmuir-Schaefer (LS) method the sample is brought to the interface horizontally.
Nanoscale films of custom thickness can be built up by repeating the deposition techniques. When using the LB and LS techniques, both hydrophilic and hydrophobic samples can be coated with a monolayer from either the liquid phase or the gas phase.
Density, thickness and homogeneity properties are preserved when transferring the Langmuir film onto the sample, giving the possibility to make organized multilayer structures with varying layer composition.
Compared to other organic thin film deposition techniques, LB is much less limited by the molecular structure of the functional molecule. This means that it is often the only technique that can be used for bottom-up assembly.
A broad range of trough dimensions and compression systems are available, for instance the new version of Alternate Langmuir-Blodgett trough.
Please, contact us to have further information!